presencestate: Allow channel drivers to provide presence state information

This patch adds the ability for channel drivers to supply presence information
in a similar manner to device state. The patch does not provide any channel
driver implementations, but it does provide the core infrastructure necessary
for channel drivers to provide such information.

The core handles multiple providers of presence state information. Ordering
of presence state is as follows:
 INVALID < NOT_SET < AVAILABLE < UNAVAILABLE < CHAT < AWAY < XA < DND

Each provider can trump the previous if it provides a presence state that
supercedes a previous one.

Review: https://reviewboard.asterisk.org/r/4050

ASTERISK-24363 #close
Reported by: Gareth Palmer
patches:
  chan_presencestate-428146.patch uploaded by Gareth Palmer (License 5169)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@429967 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 43 insertions, 26 deletions

diff --git a/main/pbx.c b/main/pbx.c
index b605a9143..267717e48 100644
--- a/main/pbx.c
+++ b/main/pbx.c
@@ -1157,10 +1157,14 @@ static int add_hintdevice(struct ast_hint *hint, const char *devicelist)
 		return -1;
 	}
 	ast_str_set(&str, 0, "%s", devicelist);
-	parse = parse_hint_device(str);
+	parse = ast_str_buffer(str);
 
-	while ((cur = strsep(&parse, "&"))) {
+	/* Spit on '&' and ',' to handle presence hints as well */
+	while ((cur = strsep(&parse, "&,"))) {
 		devicelength = strlen(cur);
+		if (!devicelength) {
+			continue;
+		}
 		device = ao2_t_alloc(sizeof(*device) + devicelength, hintdevice_destroy,
 			"allocating a hintdevice structure");
 		if (!device) {
@@ -11828,10 +11832,12 @@ static int pbx_builtin_sayphonetic(struct ast_channel *chan, const char *data)
 
 static void presence_state_cb(void *unused, struct stasis_subscription *sub, struct stasis_message *msg)
 {
-	struct ast_presence_state_message *presence_state = stasis_message_data(msg);
+	struct ast_presence_state_message *presence_state;
 	struct ast_hint *hint;
 	struct ast_str *hint_app = NULL;
-	struct ao2_iterator hint_iter;
+	struct ast_hintdevice *device;
+	struct ast_hintdevice *cmpdevice;
+	struct ao2_iterator *dev_iter;
 	struct ao2_iterator cb_iter;
 	char context_name[AST_MAX_CONTEXT];
 	char exten_name[AST_MAX_EXTENSION];
@@ -11840,38 +11846,48 @@ static void presence_state_cb(void *unused, struct stasis_subscription *sub, str
 		return;
 	}
 
+	presence_state = stasis_message_data(msg);
+
+	if (ao2_container_count(hintdevices) == 0) {
+		/* There are no hints monitoring devices. */
+		return;
+	}
+
 	hint_app = ast_str_create(1024);
 	if (!hint_app) {
 		return;
 	}
 
 	ast_mutex_lock(&context_merge_lock);/* Hold off ast_merge_contexts_and_delete */
-	hint_iter = ao2_iterator_init(hints, 0);
-	for (; (hint = ao2_iterator_next(&hint_iter)); ao2_cleanup(hint)) {
-		struct ast_state_cb *state_cb;
-		const char *app;
-		char *parse;
-		SCOPED_AO2LOCK(lock, hint);
 
-		if (!hint->exten) {
-			/* The extension has already been destroyed */
-			continue;
-		}
+	cmpdevice = ast_alloca(sizeof(*cmpdevice) + strlen(presence_state->provider));
+	strcpy(cmpdevice->hintdevice, presence_state->provider);
 
-		/* Does this hint monitor the device that changed state? */
-		app = ast_get_extension_app(hint->exten);
-		if (ast_strlen_zero(app)) {
-			/* The hint does not monitor presence at all. */
-			continue;
-		}
+	ast_mutex_lock(&context_merge_lock);/* Hold off ast_merge_contexts_and_delete */
+	dev_iter = ao2_t_callback(hintdevices,
+		OBJ_POINTER | OBJ_MULTIPLE,
+		hintdevice_cmp_multiple,
+		cmpdevice,
+		"find devices in container");
+	if (!dev_iter) {
+		ast_mutex_unlock(&context_merge_lock);
+		ast_free(hint_app);
+		return;
+	}
+
+	for (; (device = ao2_iterator_next(dev_iter)); ao2_t_ref(device, -1, "Next device")) {
+		struct ast_state_cb *state_cb;
 
-		ast_str_set(&hint_app, 0, "%s", app);
-		parse = parse_hint_presence(hint_app);
-		if (ast_strlen_zero(parse)) {
+		if (!device->hint) {
+			/* Should never happen. */
 			continue;
 		}
-		if (strcasecmp(parse, presence_state->provider)) {
-			/* The hint does not monitor the presence provider. */
+		hint = device->hint;
+
+		ao2_lock(hint);
+		if (!hint->exten) {
+			/* The extension has already been destroyed */
+			ao2_unlock(hint);
 			continue;
 		}
 
@@ -11885,6 +11901,7 @@ static void presence_state_cb(void *unused, struct stasis_subscription *sub, str
 		ast_copy_string(exten_name, ast_get_extension_name(hint->exten),
 			sizeof(exten_name));
 		ast_str_set(&hint_app, 0, "%s", ast_get_extension_app(hint->exten));
+		ao2_unlock(hint);
 
 		/* Check to see if update is necessary */
 		if ((hint->last_presence_state == presence_state->state) &&
@@ -11928,7 +11945,7 @@ static void presence_state_cb(void *unused, struct stasis_subscription *sub, str
 		}
 		ao2_iterator_destroy(&cb_iter);
 	}
-	ao2_iterator_destroy(&hint_iter);
+	ao2_iterator_destroy(dev_iter);
 	ast_mutex_unlock(&context_merge_lock);
 
 	ast_free(hint_app);